Numbers 31:13-18

13And Moses and Eleazar the priest and all the princes of the assembly went forth to meet them outside the camp.

14And Moses was wroth with the officers of the army, with the captains of thousands, and captains of hundreds, who came from the service of the war;

15and Moses said to them, Have ye saved all the women alive?

16Lo, these, through the counsel of Balaam, caused the children of Israel to commit sin against Jehovah in the matter of Peor, and there was a plague on the assembly of Jehovah.

17And now slay every male among the little ones, and slay every woman that hath known man by lying with him,

18but all the children among the women that have not known lying with a man, keep alive for yourselves.